The invention relates to a power supply system referred to conventionally as a "buried" power supply system for an urban electric vehicle equipped with collector shoes enabling energy to be collected while the vehicle is moving along a route along which a power supply track extends, the shoes coming into contact with the track. The invention relates more particularly to a system designed to equip traffic lanes or roads having power supply tracks installed at the tops of troughs provided for them in the road surface, and to electric vehicles suitable for using the system.
Moving electric vehicles which collect the energy they need from stationary power supply means with which they remain in electrical contact are generally powered via a network of overhead contact lines extending along routes provided for the vehicles or via power supply rails placed on the ground, when the vehicles run on dedicated tracks.
When overhead lines are used, a network of wires and a set of support means for the network of wires must be present permanently and such that they are unavoidable eyesores above and in the vicinity of roads. This may constitute a drawback considered as prohibitive in protected tourist sectors, and, for example, in listed urban centers.
Conversely, an electric power supply network installed by means of power supply tracks placed on the ground remedies that drawback when the power supply tracks and at least a portion of the means associated with them are disposed in preferably closed troughs that are provided in the road surfaces on which the vehicles run.
Buried power supply systems have long been known. They suffer from the drawback of requiring troughs to be provided to enable the conductive tracks to be laid in road surfaces. It is then necessary to cover the troughs when the road surfaces in which they are provided are not reserved exclusively for electric vehicles, and when it is necessary for a wide variety of vehicles and in particular two-wheelers to be allowed to pass over the troughs. In addition, for obvious safety reasons, it is essential to ensure than nothing apart from a collector shoe of an electric vehicle can be put in electrical contact with a live portion of a conductive track of such a buried power supply system.
Document EP-A-0 761 493 describes a buried power supply system that satisfies those criteria. It makes provision for a conductive track to be laid that is made up of a succession of plates that are electrically isolated from one other and that cover a trough at the bottom of which an elastically deformable strip extends containing a ferromagnetic material and whose two faces are covered with a conductive material. The top face of the strip is connected to a power supply line. The strip can be magnetically attracted by magnets carried by an electric vehicle so as to come into contact via its top face with at least one plate of the conductive track against which a collector shoe of the vehicle moves. The other plates of the conductive track, against which plates the strip rests, are connected to a very low potential via the bottom face of the strip, which face serves a power return.